The invention relates to specific amylose products suitable as matrix former for programmed release systems in the form of tablets, pellets, pills, capsules or granules. When lower down in the specification reference is made to tablets, the related designs mentioned above will also be meant.
Tablets contain, in addition to the active ingredient such as a drug (pharmacon), vitamin, cleansing agent, functional food ingredient (nutraceutical), fertilizer, growth agent, flavor, preservative, insecticide or herbicide, also specific adjuvants (excipients). These adjuvants are classified according to their functional properties, such as binders, fillers, disintegrants, matrix formers, lubricants, flavors or colors. Specific adjuvants may also have two or more functional properties.
A normal tablet gives a rapid release of the drug from the tablet. However, the properties of the tablet may be modified so as to obtain sustained release of the drug, e.g. in the gastrointestinal tract. This is referred to as programmed release, controlled release and/or sustained release. Important aims of programmed release systems are the reduction of the side effects of the drug and the enabling a lower dosing frequency. This can be realized by providing for sustained and gradual release of the drug from the release system. Thus, the drug is absorbed in the blood more gradually, and there is a better guarantee that the plasma concentration of the drug is higher than the minimum effective concentration. If it is desirable to maintain a constant blood level of the drug for a longer time, then this can often be obtained by allowing the drug to be released from the release system at a constant rate. The release with an amount constant per unit of time is designated as zero-order release or zero-order profile.
Several methods are known for the manufacture of programmed release systems. Because of their simple preparation matrix systems are often used. This preparation comprises the mixing the active ingredient, a matrix former and one or more adjuvants, followed by compression, e.g. for tabletting. Since the matrix systems slowly dissolve in the relevant water-containing environment (e.g. the gastro-intestinal tract) or since slow diffusion of water takes place in the tablet, sustained release of the active ingredient is effected.
It is an object of the invention to provide amylose products which are eminently suitable as a matrix-forming component in programmed release systems such as matrix tablets. For the manufacture of these tablets the conventional techniques can be used, namely dry granulation, wet granulation and direct compression.
The amylose products provided according to the invention are in particular very suitable for the manufacture of matrix tablets via direct compression. Here the powder mixture to be tabletted is introduced into the molds of a tabletting press and then compressed into tablets with a stamp.
It is a further object of the invention to provide a simple and efficient process for preparing such amylose products.